The present invention relates generally to elastic laminated fabric useful in the manufacture of orthotic devices, garments, shoes and the like; or in the manufacture of other body-coverings such as bandages or the like. In particular, the invention relates to expandable laminates which exhibit enhanced air and water vapor transport characteristics through the thickness thereof.
Laminated materials of the general type used in the manufacture of garments, which term includes whole body garments such as wet suits for example and partial body garments such as shorts, gloves, and limb or joint supports, for example, as well as laminated materials used in other applications where expandability of the product is of importance, heretofore have generally included: (1) knitted or woven products wherein the expandability is provided for by the knit design; (2) materials wherein extensibility is imparted to the material by physical means, such as by crimping of paper or synthetic webs; or, (3) materials which are inherently expandable such as knitted cloth-coated rubber-like products, Neoprene. In those applications where the material of construction is to be subjected to considerable stress or strain, the choice of materials has generally been limited to the knitted or woven materials, or the neoprene-type materials. Further, in those applications where the laminate is to be in contact with the body (human or animal) and also likely to be subjected to considerable stress and/or strain, the materials of choice are the knitted or woven materials inasmuch as Neoprene is somewhat uncomfortable when used by itself in a body garment. However, in certain applications, it is desired that the material not only be capable withstanding the anticipated stress or strain, but it also must possess other important properties. For example, in wet suits, the material of construction must be "water proof" and expandable to permit the suit to be applied to the person. In similar manner, in the manufacture of certain knee, elbow and leg bandages (supports), it is required that the garment be capable of being expanded to fit it over the appendage and that, once in place, that the garment aid in holding heat and moisture to the covered body part. Neoprene, alone, is extremely difficult to slide over a body part due to the friction between the body part and the Neoprene. To overcome this disadvantage, the Neoprene is laminated to a knitted layer of cotton, polyester or like material, this knitted layer being disposed next to the body part and providing improved sliding engagement of the garment with a body part to permit the application of the garment to the body part. In this laminated material, both the rubber-like substrate and the knitted layer are expandable. Neoprene, however, is a closed cell type foam which makes it desirable in wet suits and for holding heat and moisture against a body part, but which also makes the garment inappropriate for those applications where breathability of the garment is desired. "Breathability" as used herein generally denotes the transfer of heat, i.e., gas, and particularly moisture (liquid or vapor) through the thickness of the material in question.
The transfer of heat from the human body, for example, is effected naturally by the biological function of perspiring. As an athlete, for example, performs, his body uses energy and generates heat. Natural perspiration dissipates this heat through the mechanism of water elimination from the body at the skin and the accompanying cooling of the body due to the evaporation of the perspiration from the skin to the ambient atmosphere. The efficiency of this cooling process can effect the efficiency of the athlete's performance. It is desired, therefore, that there be a material which exhibits the general properties of expandability, ease of application to the body, and good breathability. A garment manufactured from such a material would provide the desired support to the body part (expandability) and provide for the efficient dissipation of body heat. Neoprene is not breathable. To the contrary, it captures heat and moisture between a garment and a body part, which in many applications, is highly undesirable.
What is needed, then, is an expandable breathable laminate that is useful in the manufacture of garments. This laminate is presently lacking in the prior art.